OLED and QLED screens differ fundamentally in the way light and colour are generated: OLED pixels *light themselves* and can be switched off individually (perfect black, high contrast), while QLED is an LCD panel with quantum dot layer and backlight (strong brightness and vivid colours). Samsung offers QLED/Neo-QLED as a particularly bright, long-lasting option with quantum dots; OLED scores with viewing angles and deep black values.

Key differences and practical implications:
- Black level and contrast: OLED achieves perfect black because individual pixels can be switched off completely; QLED requires backlighting and therefore does not usually achieve quite the same level of black (with Mini-LED/Neo-QLED, contrast is significantly better thanks to finer segmented dimming).
- Brightness: QLED/Neo-QLED can achieve higher peak brightness and is better suited for very bright rooms or sunlight compared to TV.
- Colours and colour space: QLED uses quantum dots for very strong, stable colours and a large colour volume; modern OLEDs also achieve very wide colour spaces, Samsung now also combines quantum dots in some OLED models.
- Viewing angles and uniformity: OLED continues to offer stable colours and contrast from lateral viewing angles; QLED exhibits earlier brightness and colour losses from the side.
- Durability and burn-in risk: QLED is based on inorganic materials and is considered to be more durable with a lower risk of long-lasting image residues; OLED uses organic light-emitting diodes, which can burn in under unfavourable conditions.
- Design and thickness: OLED panels are often thinner because no large-area backlighting is required; QLED/Neo-QLED can still be built very slim thanks to mini-LED backlights.
- Gaming/motion display: Both technologies offer fast response times; OLED has very short response times, QLED/Neo-QLED models offer high refresh rates and high brightness for HDR gaming.

Short recommendation for the choice:
- If you want the highest contrast depth, best viewing angles and perfect blacks (especially in a dark home cinema environment), OLED is usually the better choice.
- If you have a very bright living room, are looking for high peak HDR brightness, maximum colour stability and long colour/brightness retention, QLED/Neo-QLED is more suitable.

I am sure of this based on the manufacturer and technical information that explains the technical principles and advantages/disadvantages of both technologies.